<?php
class Mageex_AdvanceSeo_Model_System_Config_ProcessType
{

    protected static $_options;

    const ALL    	= 'A';
	const CUSTOM    = 'C';
    public function toOptionArray()
    {
        if (!self::$_options) {
            self::$_options = array(
                array(
                    'label' => Mage::helper('cron')->__('All Time'),
                    'value' => self::ALL,
                ),
                array(
                    'label' => Mage::helper('cron')->__('Custom'),
                    'value' => self::CUSTOM,
                ),
               
            );
        }
        return self::$_options;
    }

}

?>